From owner-freebsd-questions Mon Feb 22 14:57:49 1999 Delivered-To: freebsd-questions@freebsd.org Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (Postfix) with ESMTP id 72CC711627 for ; Mon, 22 Feb 1999 14:57:29 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id JAA14107; Tue, 23 Feb 1999 09:27:25 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id JAA48555; Tue, 23 Feb 1999 09:27:22 +1030 (CST) Message-ID: <19990223092721.L93492@lemis.com> Date: Tue, 23 Feb 1999 09:27:21 +1030 From: Greg Lehey To: Gustavo Vieira G C Rios , "Dan O'Connor" Cc: freebsd-questions@FreeBSD.ORG Subject: Re: assembly References: <003001be5e98$8af7fb20$0200000a@danco.home> <36D1BAB6.BB3F8701@netshell.vicosa.com.br> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93.2i In-Reply-To: <36D1BAB6.BB3F8701@netshell.vicosa.com.br>; from Gustavo Vieira G C Rios on Mon, Feb 22, 1999 at 05:14:46PM -0300 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Monday, 22 February 1999 at 17:14:46 -0300, Gustavo Vieira G C Rios wrote: > Dan O'Connor wrote: >> >> From: Gustavo Vieira G C Rios >> >>> So no system is secure, if you have a shell account and an assembler to >>> use, right ? >> >> You'd still have to have the proper file permissions to modify the >> master.passwd file. Assembly language is just a low-level programming >> language, not a security bypass. > > I don't believe (i am sorry if i am wrong, but i am a beginner)! > If i use assembly i do not need to read a file via read API, i can > access the HD directly, without to check for access permissions, > right ? No. As I said in my last message, assembler doesn't bypass the API. The system runs in two modes, user and kernel. The only way to load kernel code without permission is to write your own kernel and boot the machine with it. > If so, i can hack a UNIX system (no matter which) using assembly! No. > Am i wrong ? Yes. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message